What’s the differnce between a bush and a tree? (please leave political commentary out of this…)
height
For one thing a tree has a trunk whereas a bush is, well bushy.
Yep. No offense, but did you bother consulting a dictionary? I think the operative words are “low and densely branched.” It might even possible to prune a bush into a treee, and vice-versa. Crepe myrtles are probably considered bushes, but are frequently pruned into becoming trees. Wisteria is a vine, but can be pruned into a bush.
No offense taken. Yes, I did look in a dictionary. Most of what I’ve seen seems arbitrary. Is there a set of criteria used to determine a minimum tree height, branch density, etc.? Seems like a semanic distinction between a bush and tree. Is it otherwise?
A bit more elaborate (taken from here):
Tree = trunk with branches
Bush = no trunk
The division point is hazy and as has been said, a bush can be pruned into a small tree. I don’t think one would ever get to be 300 ft. tall though.
Your rap on the dividing line being arbitrary is sort of out of place. All definitions are arbitrary by definition. We call a spoon a spoon only because of general agreement to call it that. True, it originally comes from the Old English word for “splinter” or “chip” but those were arbitrarily chosen too. Or if they weren’t, their predecessors were at some point in the chain.
I’ll try to give you a technical explanation from a Botanist.
Get ready.
Tree = big
Bush = small
Thank you. <waits for applause>
Hmmm. This seems to be getting a bit philosophical. I agree that that angle would be a bit out of place here. Thanks for you all of your insightful answers.
What’s the difference between a conjecture and a rap? Is it in the attitude of the querious?
If a bush falls in a forest, and no one’s there to hear it, does it echo like a duck’s quack ?
This site differentiates between a bush (“a plant with intertwined woody stalks”), a shrub (“plant with multiple stalks which are less interwined and higher than those of the bush”) and a tree (“plant with only one woody stalk (trunk)”), with some pictures to “help” identify each type. Of course, we are still left with how one determines “less intertwined”…
Thanks Finch! That site is exactly the sorta’ thing I was looking for!
And just a slight hijack what is the difference between a wood and a forest?
What’s the difference between a geneologist and a gynocologist?
The geneologist looks up the family tree, while the gynocologist looks up the family bush. 
About 130 IQ points in favor of the tree…
Oh, not that Bush…
I humbly submit that any definition of bushes, shrubs and trees that relies on how many stems they have will be wrong. There are many, many types of trees that have multiple stems - for instance in Australia we even have a very commonly used name for multiple stemmed eucalyptus trees that form lignotubers (mallees). There are also many, many shrubs and bushes etc that have only one stem - to take an extreme example, would you call broccoli a tree because it only has one stem?
Pseudoscientific classification of plants by these sorts of characteristics is a bit silly really, as is trying to put scientific definitions on what are essentially common names.
As others have said, the real determinant is height and, well, bushiness…
Sorry, didn’t see PeterW’s reply above or I would have noted that he gave you a Botanist’s view while I gave you a horticulturalists view - and we both basically said that the difference was size.
As another example of the multiple trunk not being a bush only thing, the Magnolia and the Banyan are two trees that can develop the multiple trunk appearance (maybe even the reality) by having branches touch ground and take root.
There is even what’s called “Angel Oak” where large oak trees do the same thing.
There’s one magnolia in particular in Montgomery AL that takes up most of a city block. It must have dozens of trunks.
I think it comes down to size, which is arbitrary. I have tomato and pepper plants with a definite single stalk, but they aren’t trees. Juniper is called a bush when small and a tree when big. And when does a lake become a sea, or a boat become a ship?
Taxonomies that come from ‘common use’ are often not exact. When one tries to come up with exact distinctions, there are often overlaps and exceptions to the rule which leaves any definition imprecise and open to argument.
The same thing happens in trying to define precisely the difference between a vegetable and a fruit. E.g., a tomato developes exactly like a grape, and thus, by a definition based on the part of the plant, a tomato is a fruit. But the popular taxonomy demands that fruits be sweet, which leaves out the tomato. But then again, lemons aren’t sweet…
And so, differences between tree, shrub, and bush are more and less generalizations which will have their own exceptions to the rule.
Peace.
I don’t know how to define shrub, but I know one when I see it.